화학공학소재연구정보센터
Polymer, Vol.35, No.3, 573-579, 1994
Crystalline Polymer Inclusion-Compounds - Potential Models for the Behavior of Polymer-Chains in Their Bulk, Ordered Phases
Several small-molecule hosts form clathrates or inclusion compounds (ICs) with polymers. In these polymer ICs the guest polymer chains are confined to occupy narrow channels in the crystalline matrix formed by the host. The walls of the IC channels are formed entirely from the molecules of the host, and they serve to create a unique solid-state environment for the included polymer chains. Each polymer chain included in the narrow, cylindrical IC channels (ca. 5.5 angstrom in diameter) is highly extended and also separated from neighbouring polymer chains by the host matrix channel walls. The net result is a solid-state environment where extended, stretched (as a consequence of being squeezed) polymer chains reside in isolation from their neighbours inside the narrow channels of the crystalline matrix provided by the small-molecule host. Comparison of the behaviour of isolated, stretched polymer chains in their crystalline ICs with observations made on ordered, bulk samples of the same polymer are beginning to provide some measure of the contributions made by the intrinsic nature of a confined polymer chain and the pervasive, cooperative, interchain interactions which can complicate the behaviour of bulk polymer samples. In the same way that dilute polymer solutions at the THETA temperature have been effectively used to model disordered, bulk polymer phases (both glasses and melts), polymer ICs may be utilized to increase our understanding of the behaviour of polymer chains in their ordered, bulk phases, such as those found in crystalline and liquid-crystalline samples.